Remark 3.14 Efficient numerical solutions for type (REF )-() problems have been proposed in [1]}, by exploiting the robust stabilization machinery in tandem with iterative convex relaxation techniques. However, the fundamental limitation of our main result from Corollary REF  resides in the fact that its outcome depends on the initial choice of a doubly-coprime factorization of the plant. This was to be expected, and has been alleviated in part by the subsequent results from [1]}. Similarly, the outcome of the System Level Synthesis [3]}, [4]} depends on the initial choice of a realization of the plant.

